1. Field of the Invention
This invention relates generally to suspensions systems for motor vehicles. More particularly, the present invention provides a tilt control apparatus capable of providing damping for tilting motions of the chassis relative to the suspension.
2. Disclosure Information
It is well known in the motor vehicle suspension art to use stablizer bars to increase tilt stiffness of the vehicle. The amount of tilt stiffness required in a particular suspension is generally a function of the design of the suspension coupled with its intended use. Typically, the suspension is designed to provide a predetermined degree of tilt stiffness and tilt damping from the primary suspension springs and dampers (shock absorbers and struts). However, some vehicle applications required additional tilt control. For example, some vehicles carry a payload that raises the center of gravity a considerable distance from the tilt axis of the vehicle. This significantly increases the moment arm acting on the vehicle tilt axis, thereby causing the vehicle chassis and payload to tilt relative to the suspension. Similarly, some vehicles undergo high speed cornering, creating high lateral acceleration which significantly increases the moment acting on the vehicle causing the vehicle chassis to tilt relative to the suspension.
In operation, the suspension is unable to deflect responsive to minor disturbances in the road surface due to resistance presented by the stablizer bar. These disturbances therefore transfer into the chassis of the vehicle. Unfortunately, this may have a deleterious effect on the customer's perception of the ride quality of the vehicle. Objectionable noises may be heard in the passenger compartment of the vehicle. These noises become increasingly noticeable with increasingly stiff stabilizer bars. Similarly, these minor disturbances may be perceived by the customer as objectionable jarring vibrations. It is difficult to achieve optimal damping for both tilting motion and bouncing motion of the body using traditional suspension designs.
It would be desirable to have a tilt control apparatus capable of providing additional tilt damping and stiffness for resisting very large tilt moments without imparting undesirable noises and jarring vibrations on the vehicle chassis.